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A023588
a(n) = sum of exponents in prime-power factorization of 2*prime(n)-1.
1
1, 1, 2, 1, 2, 2, 2, 1, 3, 2, 1, 1, 4, 2, 2, 3, 3, 2, 2, 2, 2, 1, 3, 2, 1, 2, 2, 2, 2, 4, 2, 3, 3, 1, 4, 2, 1, 3, 3, 3, 3, 2, 2, 3, 2, 1, 1, 2, 2, 1, 3, 3, 2, 2, 4, 4, 2, 1, 2, 3, 2, 4, 1, 4, 4, 2, 1, 1, 4, 2, 3, 2, 1, 2, 1, 4, 3, 2, 3, 2, 4, 2, 3, 2, 1, 3, 3, 2, 2, 3, 2, 3, 2, 3, 1, 3, 3, 2, 3
OFFSET
1,3
LINKS
FORMULA
a(n) = A001222(A076274(n)). - R. J. Mathar, Mar 10 2011
MATHEMATICA
Array[Plus@@Last/@FactorInteger[2*Prime[ # ]-1]&, 6! ] (* Vladimir Joseph Stephan Orlovsky, Feb 28 2010 *)
Table[Total[FactorInteger[2p-1][[;; , 2]]], {p, Prime[Range[100]]}] (* Harvey P. Dale, May 30 2024 *)
CROSSREFS
Sequence in context: A067148 A035228 A035164 * A175242 A355770 A225843
KEYWORD
nonn
STATUS
approved